1. Technical Field
The present disclosure relates to liquid crystal displays (LCD) and methods for using the same, and particularly to an LCD module capable of preventing an image tearing effect and a method for using the same.
2. Description of Related Art
Liquid crystal displays (LCD) are widely used in electronic devices for displaying images. In use, an LCD is mounted on an electronic device and is connected to a central processing unit (CPU) of the electronic device. The CPU sends image data to a random access memory (RAM) of the LCD to temporarily store the image data, and the LCD displays images according to the image data currently stored in the RAM.
When using the electronic device to play a video file, the LCD need to display a plurality of images in a predetermined order at a predetermined speed, such that the continuous displayed images form a video. Thus, when the electronic device plays a video file (i.e., formed by a plurality of images), the CPU periodically sends image data of the video file to the RAM of the LCD to temporarily store and periodically renew the image data, and the LCD periodically displays images according to the image data currently stored in the RAM. After the LCD displays an image corresponding to the data currently stored in the RAM, the CPU sends new image data to the RAM to renew the stored data, and the LCD to display a next image according to the renewed image data. In this way, the plurality of images of the video file can be continually displayed.
However, in the electronic device, the CPU and the LCD may have different working frequencies. Therefore, speed of renewing the data stored in the RAM can be different to the speed of displaying images according to the currently stored data, which may cause the CPU and the LCD to work asynchronously. For example, referring to FIG. 4 and FIG. 5, which are sequence diagrams of two typical electronic devices used to display images. Working signals of the CPU in a high electric level indicate that the CPU is renewing the data stored in the RAM, and working signals of the LCD in a high electric level indicate that the LCD is displaying images according to the currently stored data. In the times A, B shown in FIG. 4 and the times C, D shown in FIG. 5, the CPU begins and does not completely renew the data stored in the RAM, and the LCD has already begun to display images according to data currently stored in the RAM. Thus, some renewed data and some old data requiring to be renewed may be both stored in the RAM, and an image including both a part corresponding to the renewed data and another part corresponding to the old data will be displayed by the LCD. This error is called a “tearing effect”.
Therefore, there is room for improvement within the art.